We report on DNA genotyping by melting curve analysis (MCA) in a plastic foil-microfluidic system using silicon photomultiplier (SiPM) detectors. Matching and single base mismatching DNA oligonucleotides were immobilized on thin-film foil microheaters and integrated in microfluidic channels using lamination foils. Two SiPMs, each with a sensitive area of 1.2×1.2 mm were assembled in an optical measurement setup to monitor the decaying Cy3 fluorescence intensity of the hybridized DNA spots upon melting. Successful detection of single nucleotide polymorphisms (SNP) is demonstrated.